title: Comparative in vitro safety analysis of dyes for chromovitrectomy: indocyanine green, brilliant blue green, bromophenol blue, and infracyanine green.
abstract: OBJECTIVE
  Vital dyes such as infracyanine green (IfCG), brilliant blue green (BBG), and bromophenol blue (BPB) have been used as an alternative to indocyanine green (ICG) during chromovitrectomy. We compared the in vitro toxicity of IfCG, BBG, and BPB with ICG on the retinal pigment epithelial cells and retinal ganglion cells at various concentrations to optimize the safe dose and duration of exposure.
  
  
  METHODS
  Cultured retinal ganglion cells (RGC-5) and human retinal pigment epithelial cells (ARPE-19) were exposed to 2 concentrations (0.25 and 0.5 mg/mL) of ICG, IfCG, BBG, and BPB at various time intervals (1, 5, 15, and 30 minutes). Cell viability was quantified with neutral red assay, and mode of cell death was evaluated with flow cytometry-based Annexin V and propidium iodide staining.
  
  
  RESULTS
  Exposure to ICG resulted in 48%-74% reduction in neutral red uptake in both RGC-5 and ARPE-19 cells, after an exposure time of ≥5 minutes compared with control (P < 0.001). Infracyanine green, BBG, and BPB were significantly less toxic on the 2 cell lines at exposure times <15 minutes. (Reduction in cell viability ranged from 6.9% ± 3.3% to 29.3% ± 7.4% when compared with control, P > 0.5.) However, among the newer dyes, BBG caused necrosis in retinal pigment epithelial cells and retinal ganglion cells as the exposure time period increased beyond 5 minutes.
  
  
  CONCLUSIONS
  Newer vital dyes, IfCG, BBG, and BPB, are significantly less toxic on retinal ganglion cells and retinal pigment epithelial cells' cell lines when compared with ICG. Infracyanine green was least toxic among the three newer dyes studied.
authors.affiliation: Department of Ophthalmology, University of Florida College of Medicine, Jacksonville, Florida 32209, USA.
authors.forename: Sankarathi
authors.initials: S
authors.lastname: Balaiya
authors.forename: Vikram S
authors.initials: VS
authors.lastname: Brar
authors.forename: Ravi K
authors.initials: RK
authors.lastname: Murthy
authors.forename: Kakarla V
authors.initials: KV
authors.lastname: Chalam
mesh_terms: D000818:Animals; D017209:Apoptosis; D001978:Bromphenol Blue / Q000633:toxicity*; D002470:Cell Survival; D002478:Cells, Cultured; D004396:Coloring Agents / Q000633:toxicity; D005434:Flow Cytometry; D006801:Humans; D007208:Indocyanine Green / Q000031:analogs & derivatives* / Q000633:toxicity*; D051381:Rats; D012165:Retinal Ganglion Cells / Q000187:drug effects*; D055213:Retinal Pigment Epithelium / Q000187:drug effects*; D012394:Rosaniline Dyes / Q000633:toxicity*; D014821:Vitrectomy
chemical_list: D004396:Coloring Agents; C116320:Infracyanine green; D012394:Rosaniline Dyes; D001978:Bromphenol Blue; D007208:Indocyanine Green; C004692:coomassie Brilliant Blue